HOUSTON (CBSDFW.COM/AP) — The U.S. government has confirmed a 16-year-old Guatemalan child died Monday at a Border Patrol station in South Texas, the fifth death of a migrant child since December.

U.S. Customs and Border Protection said in a statement that Border Patrol apprehended the teenager in South Texas’ Rio Grande Valley on May 13. The agency says the teenager was found unresponsive during a welfare check at the agency’s Weslaco, Texas, station. The teenager’s cause of death is unknown.

The agency did not say why the teenager had been detained for a week, but said he was “due for placement” in a facility for youth operated by the U.S. Department of Health and Human Services.

Federal law requires the Department of Homeland Security to send minors unaccompanied by a parent or legal guardian to HHS within 72 hours of determining that the child is unaccompanied.

After the deaths of two children ages 7 and 8 in December, the Department of Homeland Security ordered medical checks of all children in its custody and expanded medical screenings.

Trump administration officials have said they have passed a “breaking point” in the immigration detention system, with the numbers of parents and children crossing the border dramatically exceeding the capacity at facilities.

That strain is particularly acute in the Rio Grande Valley, which has more unauthorized border crossings than any other region.

The Border Patrol has released photos of adults and children lying in small, military-style tents or on the grass and pavement outside of two of its stations. It also recently opened a 500-person tent near one port of entry and announced plans to open another.